When fully implemented, these new standards will reduce soot or particulate matter (PM) by 90 percent or 27,000 tons and reduce nitrogen oxides emissions (NOx) by 80 percent or nearly 800,000 tons. Nationwide this regulation will help prevent 1,400 premature deaths, and 120,000 lost workdays annually in 2030. The estimated annual health benefits are valued between $8.4 billion and $12 billion. When these older locomotive and marine engines reach the end of their useful life, and new engines enter into the nation’s diesel fleet, the benefits of today’s action will increase.

Edward R. Hamberger, president of the Association of American Railroads, said he is confident his industry could comply.

“Our locomotive builders will be required to design diesel particulate filters and selective catalytic reduction systems that can fit within the narrow confines of a locomotive and withstand the harsh railroad operating environment,” Hamberger said in a statement. “In meeting the emissions limits established by the previous standards, the railroad industry has achieved emissions and energy efficiencies beyond those contemplated at the time the previous standards were issued.”

Tightening requirements from ships coming from outside the U.S. would be a good next step, given all the pollution-related health problems among those who live near California ports. Senator Barbara Boxer has introduced legislation that would require oceangoing vessels that visit U.S. ports to use cleaner fuel and cleaner engines; at a hearing last month, she stated that foreign-flagged ships emit almost 90% of the vessel pollution in the U.S.